The Space Development Agency (SDA) is a
United States Space Force direct-reporting unit tasked with deploying disruptive space technology.[1] A primary focus is space-based
missile defense using large global
satellite constellations made up of industry-procured low-cost satellites.[2][3][4] The SDA has been managed by the
United States Space Force since October 2022.[5] By February 2024 the SDA had 33 satellites on orbit.[6] SDA targets to have at least 1,000 satellites in
low Earth orbit by 2026.[7]
The Space Development Agency proposed the National Defense Space Architecture,[12][13][14] later renamed the Proliferated Warfighting Space Architecture.[a] It advances a network of global orbiters composed of layers with different military capabilities such as communications, surveillance, global navigation, battle management, deterrence, and missile defense. The
satellite constellation is to be interconnected by
free-space optical laser terminals[15] in a secure command and control
optical mesh network.[16] Satellites are to be low cost and "proliferated" in low Earth orbit. New commercial technology such as
reusable launch systems have reduced deployment costs[17] and new mass-produced commercial satellites offer less "juicy" targets for
anti-satellite weapons by being inexpensive and potentially hard to distinguish from other commercial satellites.[2] Development is to follow the
spiral model,[b][c] incorporating learning from previous iterations and launching new satellite replacements regularly as the useful lifetime of each is relatively short. The SDA expects to field and maintain a constellation of at least 1,000 satellites on orbit by 2026.[7]
The SDA has mostly avoided flaws that plagued earlier proliferated missile defense programs such as
Brilliant Pebbles. The
Anti-Ballistic Missile Treaty was a major impediment in the past, as these systems were deemed non-compliant with the treaty by Congress.[9] However,
George W. Bush withdrew the United States from the treaty in 2002, eliminating this barrier.[18] Over the years, launch and manufacturing costs have been greatly reduced. Decades after the
SDIO’s
DC-X failed there are now commercial
reusable launch vehicles such as
SpaceX's
Falcon 9 rocket.[19] Meanwhile
mass manufacturing as with
Starlink has proven the potential for lower satellite build costs.[17]
Political and administrative opposition to SDA came from 24th Secretary of the Air Force
Heather Wilson who argued that "launching hundreds of cheap satellites into theater as a substitute for the complex architectures where we provide key capabilities to the warfighter will result in failure on America's worst day if relied upon alone."[7] Members of Congress also gave concerns that SDA would drain resources and jobs from Air Force and questioned why DoD had to create a separate organization to circumvent its own procurement process. Despite the pushback, the Pentagon did not require congressional authorization to create the SDA, and Wilson was overruled by
Patrick M. Shanahan, who became acting defense secretary by appointment of
Donald Trump. He placed the new agency under the authority and control of
Mike Griffin who was also appointed as
Under Secretary of Defense (R&E).[8]
Critics have reiterated longstanding concerns that ground-based lasers can easily "paint" satellites in low Earth orbit, temporarily blinding their sensors. The APS reporting the energy needed for this is very low.[23] Likewise,
RF jamming is simpler when communication and radar satellites are in lower altitudes as less power is needed to saturate their
low-noise amplifiers. It is also far easier to launch an
anti-satellite weapon to destroy satellites in low Earth orbit (as demonstrated with small
ASM-135 or
RIM-161 missiles) given much less energy is required to kinetically intersect than to enter and maintain orbit. An adversary would simply need to "punch a hole" in the constellation immediately before launching an attack.[24][20][25] When the
Biden administration took ownership of the program in 2021, they appeared to take heed of these concerns[26] but still signed on to a $500M increase for the agency in the FY2023 spending bill.[27]
The Heritage Foundation, a conservative think tank, called the Space Development Agency a model for the military. In their 2025 Mandate for Leadership, they call to develop new offensive space capabilities to "impose [American] will if necessary". They further claim the Biden administration "has eliminated almost all offensive deterrence capabilities" in space that were planned under the Trump administration.[28]
SDA awarded its first contracts in August 2020.
Lockheed Martin received $188 million and York Space Systems received $94 million to each build 10 data relay satellites for its transport layer. In October 2020, SDA chose
SpaceX and
L3Harris Technologies to develop four satellites each to detect and track ballistic and hypersonic missiles.[31] The initial tranche of satellites were originally scheduled to launch September 2022.[16] However, the initial launch slipped due to supply-chain issues for microelectronics such as radios,[32] software problems, and protests by
Raytheon and
Airbus over procurement and evaluation process.[33] SDA industry partners now include
SpaceX,
L3Harris Technologies,
Northrop Grumman,
Ball Aerospace and
General Dynamics.[7]
A number of experimental satellites were launched in 2021. SDA plans to test some of the key technologies in a series of on-orbit experiments that went up on
Transporter-2: Mandrake 2, the Laser Interconnect and Networking Communications System (LINCS), and the Prototype On-orbit Experimental Testbed (POET).[34]
SDA's current schedule expects Tranche 0 capability[c][d] will be on orbit in time to support a summer 2023 demonstration.[33][35][36][37]Link 16 connectivity between
Five Eyes nations, via Low Earth Orbit Tranche 0 satellites was demonstrated from 21 November to 27 November 2023.[38][39] Global coverage of missile launches will take 40 downward-looking satellites.[40] By year-end 2025 there will be 126 Link-16 satellites in orbit for intercommunication, using Tranche 1 Tracking capabilities.[41] Tranche 2 Tracking capability will start in 2026.[41]
Tranche 1 satellites were solicited for bid in 2021,[42] launch in September 2024,[43] with monthly launches thereafter.[44][45] More than 150 satellites: 126 in Tranche 1 Transport Layer; 35 in Tranche 1 Tracking Layer; 12 in Tranche 1 Demonstration and Experimentation System.[44] In 2022 contracts were awarded to York Space Systems, Lockheed Martin Space, and Northrop Grumman Space Systems.[46]
Tranche 2 satellites were solicited for bid in 2023,[47] for launch in 2026.[47] More than 550 satellites: 250 in the Transport Layer; 50 in the Tracking Layer; Transport Layer will have 100 Alpha satellites, 72 Beta satellites, and 44 Gamma satellites;[44] The Beta satellites RFP were released in the 2nd week of April.[44] The Alpha RFP was released in June 2023 and Gamma is scheduled for early 2024.[44] The Alpha satellites are similar to those in the Tranche 1 Transport Layer; the Beta satellites will have UHF and tactical communications payloads; the Gamma satellites will carry advanced waveform payloads.[44][48] York Space Systems will build 62 satellites for the Tranche 2 Transport Layer.[49] In 2023 contracts for 72 satellites were awarded to Northrop Grumman and Lockheed Martin (for 36 Beta satellites apiece).[50][51][52][53] In 2024 a third vendor, Rocket Lab LLC, was selected to supply 18 space vehicles, an additional part of the Beta Tranche 2 Tracking Layer (T2TL) tranche, for a total of 90 space vehicles in the Beta T2TL tranche.[54]
On 16 January 2024, the SDA announced an award to three vendors worth up to $2.5 billion. These vendors will supply "preliminary fire control" satellites in the Tranche 2 Tracking Layer. They will carry infrared (IR)
cameras, with a mix of
fields of view (FOVs).[55][56] The FOVs in the IR cameras will be either wide FOV (WFOV), or medium FOV (MFOV) for low-resolution, or higher-resolution tracking capability respectively.[55] If such a satellite were to prove performant, and launched early, and no later than April 2027, a vendor could receive an incentive payment.[55] Each vendor is to provide 18 satellites, of which 16 are to carry WFOV cameras; the remaining two are to be MFOV cameras.[d][56][55] The Proliferated Warfighting Space Architecture (PWSA) will rely on these preliminary fire control satellites to perform the
JADC2 concept.[55] Tranche 2 Tracking capability will start after the 2026 launches.[41]
Projects and research
SDA satellites are the first to have direct-to-weapon control according to SDA's technical director, Frank Turner.[62]
The
satellite constellations are in
near-polarlow Earth orbit.[78] Hundreds of satellites are expected by the end of the 2020s.[14] "Would you be able to take out some of these satellites? Probably. Would you be able to take out all of these satellites? Probably not, before you are going to have a really bad day."—Derek Tournear [79]: min -2:10 before the end of the video clip [80][70]
NExT (National Defense Space Architecture (NDSA)[a] Experimental Testbed)[c] is a test bed of 10 space vehicles and associated mission-enabling ground systems, for realizing its various aspects, in miniature, before its larger, later scheduled deployments. In particular, the capability to retain and/or relay messages for
command and control (C2) can then be demonstrated on the NExT test bed, before deployment at scale.[81][82]
Using the satellites of Tranche 0, the SDA will be demonstrating the new capabilities[c] of the PWSA[a] to the warfighters, to aid in concept development (using the "warfighter immersion tranche").[83][59][43]
User equipment (
Earth stations and weapon systems)[79][88] SDA has selected the "ground Operations and Integration (O&I) segment for Tranche 1".[89]
Transport layer intersatellite data[78] Tranche 1 Transport Layer (T1TL):[57] T1TL forms a
mesh network in a constellation of small satellites in Low earth orbit (LEO). Each satellite would have 4 optical links.[42] SDA may have awarded 3 contracts totalling $1.8 billion to 3 firms, each for 42 satellites to be launched by September 2024.[57][86] However, there was a funding constraint in the FY2022 budget.[90][91][92]
Tracking layer handles launched items,[93] connects to existing user equipment[13][90][88][94][95] Two contractors will each build 14 satellites for the Tranche 1 Tracking Layer as of 16 July 2022; these satellites will be in Low Earth Orbit (LEO) by 2025; hundreds of satellites are planned for the Tracking layer.[96] The Tracking Layer is capable of tracking hypersonic missiles throughout their flight, by their heat signatures.[96][97][58][98]
Custody layer[99] handles items not yet launched from objects as big as a truck,[100] connects to existing user equipment[13]
SDA's initial launch of 10 satellites (denoted Tranche 0)[c] had been scheduled for December 2022; however tests of 8 of these satellites indicated that each had a
noisy power supply. The contractor, York Space Systems retrofitted filters on the 8 satellites at no cost to the government; the initial launch was delayed to March 2023, including the 8 retrofitted by York Space Systems.[111][35]
On 2 April 2023 the first 10 satellites of Tranche 0 were launched into low earth orbit, as planned. These satellites will demonstrate the responsive (low latency) communication links of the Transport layer of the Proliferated Warfighter Space Architecture (PWSA). An initial checkout of the satellite bus and mission[c] payloads is the current priority.[111] The second Tranche 0 launch, carrying 13 more satellites, took place on 2 September 2023.[113] Of the 18 initially scheduled payloads one Transport satellite built by York has been excluded to conduct software tests, while the four Tracking satellites built by
L3Harris had been kept on the ground by production delays and were launched later as rideshare payloads of a
USSF-124 mission in February 2024.[114]
SDA began as a
direct reporting unit (DRU) of DoD's USD(R&E): research and engineering.[b] By design,[117] the functions for
acquisition and sustainment (A&S) are the responsibility of
another under secretary of defense —the USD(A&S); this separation of function decouples the technology development of a working prototype system, even the systems as complicated as those taken on by the SDA, from overcomplication induced by the processes of the DoD.[G][h]
The SDA has relied heavily on "Section 804" Mid-Tier Acquisitions (MTAs) to avoid traditional defense procurement requirements. SDA has been able to forgo a number of reporting activities by breaking up larger programs into numerous two-year rapid fielding projects that each qualify as MTAs. Members of Congress and the
Government Accountability Office have said this obfuscates costs and limits transparency. The FY23 omnibus appropriations act, signed by
President Joe Biden on 29 December 2022, levies new reporting and certification requirements on the Pentagon regarding the use of MTAs and other rapid prototype programs. Industry participants such as
MITRE Acquisition Chief Pete Modigliani have said the new requirements would "drastically impede DoD’s rapid acquisition abilities" for SDA and other programs.[237]
^
abcdefghThe name change of the constellation from NDSA to PWSA —'proliferated warfighter space architecture'— will have no impact to the SDA mission.[85]
^
ab"The OUSD(R&E) will develop critical technologies, rapidly prototype them, and conduct continuous campaigns of joint experimentation to improve on those technologies and deliver capabilities", —Hon.
Heidi Shyu, head of the office of the undersecretary of defense for research and engineering (OUSD(R&E)).[115][116]
^
abcdefTranche 0 will demonstrate the feasibility of
^
abcSpace development agency (SDA) provides the PWSA wide field of view (WFOV) sensors;
Missile defense agency (MDA) provides the
Hypersonic and Ballistic Tracking Space Sensor (HBTSS) sensors, (i.e., the Medium Field of View (MFOV) sensors). The WFOV sensors provide cueing data to the MFOV sensors, which are more sensitive and provide tipping data to the
earth-based interceptors.[104] as cited in USNI News.[105] Two WFOV satellites were launched as part of the inititial Tranche 0.[35]
^In September 2021 the Space Development Agency approved design plans for its new missile warning satellites, which will be capable of detecting and tracking hypersonic weapons.[75][58]
L3Harris Technologies announced that the Space Development Agency has approved the company’s proposed design for a missile tracking satellite.[76] A production contract for 16 Tranche 1 Tracking satellites to track hypersonic missiles, for launch in 2025, was approved.[77]
SpaceX will build 4 satellites for the Tranche 0 tracking layer.[35]
^In Remote Sensing, Tipping and Queuing (Cueing) is a technique for tracking and monitoring fast-moving objects, using multiple sensors of multiple modalities (for example electro-optical and radar sensors). One sensor with a wide field of view might detect, acquire, and even track an object of interest (the 'target'); that sensor would 'tip' another sensor with the tracking information for that target. The next sensor, say with point defense capability, might then take the 'cue' to narrow the tracking box around the target, to build more accurate tracking information, to tip yet another defense system, and so forth. See
Automatic identification system (AIS)[103]
^Proliferated Low earth orbit satellite-based services, awarded under indefinite delivery/indefinite quantity (IDIQ) contracts. Services for Space Systems Command include high-speed broadband, synthetic aperture radar imaging, space domain awareness; and alternative positioning, navigation and timing.[263]
^
abBaucom, Donald (2004).
"The Rise and Fall of Brilliant Pebbles"(PDF). The Journal of Social, Political, and Economic Studies. 29 (2).
Archived(PDF) from the original on 2023-03-07. Retrieved 2023-01-03.
^"2022 National Defense Strategy"(PDF). Office of the Secretary of Defense. 27 October 2022.
Archived(PDF) from the original on 17 January 2023. Retrieved 10 November 2022.
^
abcTheresa Hitchens
(28 Oct 2021) SDA Scraps, Relaunches Data Transport Satellite Bidding After Protest Archived 28 October 2021 at the
Wayback Machine Tranche 1: T1TL of Aug 2021 was rescinded: "126 satellites [each] with Ka-band space-to-ground communications link, four optical communications terminals, a Link 16 payload (which is the current standard for machine-to-machine communications link among US and allied weapon systems), and a battle management, command, control and communications (BMC3) compute and storage module"; T1TL RFP was reissued 28 Oct 2021. T1TL terms were replaced with OTA authority instead. Proposals were due 24 Nov 2021.
^
abCenter for Strategic & International Studies
(7 Feb 2022) Complex Air Defense: Countering the Hypersonic Missile ThreatArchived 23 September 2022 at the
Wayback Machine Dr. Tom Karako, Director of the CSIS Missile Defense Project; Ms. Kelley Sayler, CRS; Dr. Gillian Bussey, Director of the Joint Hypersonics Transition Office; Dr. Mark Lewis, Executive Director of NDIA's Emerging Technologies Institute; Mr. Stan Stafira, Chief Architect at the Missile Defense Agency (MDA)
^
abSecretary of the Air Force Public Affairs
(19 Sep 2022) Air Force taps Brig. Gen. Luke Cropsey to head new integrated C3 battle management programArchived 23 March 2023 at the
Wayback Machine Command, Control, Communications and Battle Management (C3BM). USAF general Cropsey will have the authorities required to ensure integration of all C3BM related programs throughout the DAF, as a core contribution to the Department of Defense's broader Joint All Domain Command and Control (JADC2) effort. [Integrating] PEO will also have responsibility for the Advanced Battle Management System (ABMS).
^DoD
(8 Dec 2022) Seven Nations Meet to Address Space SecurityArchived 19 December 2022 at the
Wayback Machine CSpO Principals Board: Australia, Canada, France, Germany, New Zealand, the United Kingdom, and the United States met in NZ. Included: Dr. John Plumb, Assistant Secretary of Defense for Space Policy; U.S. Space Force Gen.
Chance Saltzman, Chief of Space Operations; U.S. Army GEN
James H. Dickinson, Commander, United States Space Command; and Mr. Damon Wells, National Reconnaissance Office
Theresa Hitchens
(12 October 2020) SMDC Pushes For New PNT, Tracking Sat PayloadsArchived 18 May 2023 at the
Wayback Machine In addition to the 3 LEO satellite programs mentioned above, SMDC's technical center is working on project TITAN (Tactical Intelligence Targeting Access Node), a "common, mobile ground station" for the Army's tactical needs. This is part of the Positioning, Navigation and Timing (PNT) capability.
^Washington Headquarters Service (WHS)
(2010) Plain LanguageArchived 2022-06-28 at the
Wayback Machine Official DoD Plain Language Website — DoD Instruction 5025.13, "DoD Plain Language Program".
^Amanda Miller
(3 Nov 2022) Refining the JADC2 ConceptArchived 30 November 2022 at the
Wayback Machine "Agreeing to share data is easy. Actually doing it is hard". —Derek M.Tournear, SDA: °First) beyond-line-of-sight targeting. "Think mobile missile launchers—think ships. Detect them. Track them. Calculate a fire control solution and send it down directly to the war fighter so they can use that in their solution"; °Second) enable that same thing 'for advanced missiles in flight'. That is, to detect and track a hypersonic glide vehicle in flight, then "calculate a fire control solution [and] send it down to an interceptor to take out that threat immediately".
^Theresa Hitchens
(1 Jul 2021) SMC Eyes MEO Sats For Missile TrackingArchived 2 July 2021 at the
Wayback Machine Raytheon & Boeing Millennium Systems are designing digital prototypes which are in Critical design review (CDR) by Space and Missile Systems Center (SMC) for launch to MEO in late 2022. Missile Track Custody Prototype (TCD)
^Daviscourt, Joshua (28 June 2021).
"COTS and Space-based Missile Defense". United States Air Force.
Archived from the original on 5 December 2021. Retrieved 1 December 2021. This article incorporates text from this source, which is in the
public domain.
^Theresa Hitchens
(11 Nov 2022) Space Development Agency missile tracking data will inform NC3Archived 12 November 2022 at the
Wayback Machine "While the timeframe for certifying SDA's Tracking Layer as part of the nuclear attack sensor network remains unclear, SDA Director Derek Tournear said there is 'plenty of time' to get it done". SBIRS and next-gen OPIR satellites are already ITWAA-certified. 2025-26 time frame.
^Theresa Hitchens
(21 Nov 2022) SDA ponders signal, tech trade-offs for alternate GPS satellite payloadsArchived 21 November 2022 at the
Wayback Machine "SDA is considering signals different to GPS, but offered within the same frequency bands. If SDA’s military PNT service is located within the existing GPS frequency bands, it will minimize integration cost of new antenna systems on terrestrial weapon systems". Positioning, Navigation and Timing (PNT)
^Sandra Erwin
(1 Feb 2023) Space Development Agency issues draft solicitation for 72 satellites beta 2026 Tranche 2 Transport Layer: "The Space Development Agency is planning a new procurement of 72 satellites to continue to build out a military constellation in low Earth orbit". Part of a 216 satellite tranche. 6 orbital planes.
^Sandra Erwin
(27 Nov 2023) Additional vendors selected for DoD's low Earth orbit satellite services contract The 20 vendors: first 16 are: ARINC, Artel, Capella Federal, BlackSky, SES, Hughes, Viasat, KGS, Intelsat General, OneWeb, PAR Government, RiteNet Corporation, Satcom Direct Government, SpaceX, Trace Systems and UltiSat; the additional 4 vendors are AT&T, Honeywell Aerospace, Iridium and Lynk Global.